114560domain: NAppears in sequencesNumber of Apollonian packings of n circles that are Eulerian and irreducible.at n=17A171090Coefficient of x in the reduction by x^2->x+1 of the polynomial p(n,x) defined below in Comments.at n=20A192747Starts of runs of 3 consecutive integers that are Wythoff-Niven numbers (A364006).at n=19A364008